给定一个二叉树，返回所有从根节点到叶子节点的路径。
说明: 叶子节点是指没有子节点的节点。
示例:
输入: 1 / 2 3 5 输出: ["1->2->5", "1->3"] 解释: 所有根节点到叶子节点的路径为: 1->2->5, 1->3
# Definition for a binary tree node. # class TreeNode: # def __init__(self, x): # self.val = x # self.left = None # self.right = None class Solution: def binaryTreePaths(self, root): """ :type root: TreeNode :rtype: List[str] """ path=‘‘ result=[] self.echo(root,path,result) return result def echo(self,root,path,result): if not root: return path+=str(root.val) if root.left: self.echo(root.left,path + ‘->‘,result) if root.right: self.echo(root.right,path + ‘->‘,result) if not root.left and not root.right: result.append(path)
原文：https://www.cnblogs.com/flashBoxer/p/9532400.html